There is a huuuuuge topic on french forum radiocockpit (
RadioCoco • Page d?index)
Lagos was a short stop to board some pax. The crew failed to arm AT before departure.
On takeoff, pushing TOGA didn't engage AT (for cause, it wasn't armed).
Instead of applying procedure (manually set thrust and think about it later), the captain tried to arm AT. But instead, engaged Auto Pilot.
On VR, captain felt the controls were heavy, thought on a stabilizer jam, and decided to reject.
According to Boeing Statement, there is 7 another cases of AP unattentioned engagement during takeoff roll.
It seems a soft update is in development to prevent engaging AP on ground.